Surveys, boundaries and acreage
The acreage in a listing almost always comes from an assessor record, not from a survey. Fences are frequently in the wrong place. If exact boundaries matter to you, only a licensed surveyor can establish them.
How land gets described
Two systems dominate, and you will see both depending on where the land is.
- Public Land Survey System
- Used across most of the Midwest and West. Land is divided into townships six miles square, each containing 36 sections of roughly 640 acres, and parcels are described as aliquot parts such as the northeast quarter of the southwest quarter of a section.
- Metes and bounds
- Used in the original colonies, Texas and parts of the South. The parcel is described by bearings, distances and monuments, walking the boundary in sequence back to the point of beginning.
- Lot and block
- Used in platted subdivisions. The parcel is a numbered lot on a recorded plat, which is the simplest description to work with.
Why the acreage figure is approximate
The acreage shown in a listing usually comes from the county assessor, which derives it from tax maps built for valuation rather than for conveyance. It is not a measurement of your boundary.
Differences of a few percent are routine. Larger differences happen, particularly on older metes and bounds descriptions, on parcels split informally over generations, and where a road right of way crosses the parcel and may or may not have been deducted.
If you are paying by the acre on a large tract, the difference between deeded acreage and surveyed acreage is real money. Decide before signing who bears that risk.
What a survey actually gives you
A boundary survey locates the corners on the ground, sets or recovers monuments, and produces a plat showing the parcel as measured. That is what you need in order to know where to fence, where to build and where your neighbour ends.
An ALTA/NSPS survey is the more detailed commercial product. It adds easements, improvements and encroachments, and it is what a lender or a title insurer usually wants on a significant transaction.
A survey also surfaces encroachments: a neighbour’s shed, a shared driveway, a fence built decades ago in the wrong place. Discovering these before closing is inconvenient. Discovering them afterwards is a dispute.
Fences, occupation lines and adverse possession
A fence is evidence of where somebody once thought the line was. It is not the line.
Where a fence has stood in the wrong place for a long period, state doctrines such as adverse possession, acquiescence or boundary by agreement can in some circumstances move the legal boundary. The requirements are specific, they vary by state, and they are resolved by courts rather than by assumption.
The practical point for a buyer is simple: if you intend to rely on the fence line, have the boundary surveyed before you buy, not after you have built against it.
When to pay for a survey
Always, if you are buying by the acre on a large tract, building near a boundary, subdividing, relying on a fence line, or buying a parcel described in metes and bounds that has never been surveyed.
Often worth it if the parcel has no recent plat, if neighbouring use appears to cross the line, or if access runs along a boundary.
Less critical for a platted subdivision lot with recent monuments, where the plat already does most of the work.
Mapping applications and parcel viewers are useful for orientation and are not survey grade. Do not set a fence or a building from one.
Common questions
Is the acreage in a listing accurate?
It is the figure the listing agent entered, usually from the county assessor record. It is not a survey and should be treated as approximate, particularly on older or irregular parcels.
How much does a boundary survey cost?
It depends on the size and shape of the parcel, the terrain, the vegetation, and how much research the surveyor needs to do to recover corners. Get two or three quotes locally; an irregular, wooded, never-surveyed tract costs considerably more than a platted lot.
What is a section of land?
In the Public Land Survey System, a section is one square mile, nominally 640 acres. A quarter section is about 160 acres and a quarter-quarter about 40 acres, which is why so many parcels in the West come in those sizes.
Does title insurance cover boundary problems?
A standard policy typically excepts matters that an accurate survey would disclose. Removing that exception generally requires providing a survey. Read the exceptions in the commitment and ask the title company directly.
Check it with the source
This is general information, not legal, engineering or financial advice. Rules vary by state and county and they change. Get the answer that matters to you in writing from the office that issues it.
Related guides
Legal access and easements
A road touching a parcel on a map is not a right to drive on it. Legal access is the single most expensive thing to get wrong when buying rural land, because without it a parcel can be difficult to build on, insure, finance or resell.
Mineral rights on land you buy
In the United States, the rights to the surface of a parcel and the rights to the minerals beneath it can be owned by different people. Where they have been separated, the mineral owner usually has the stronger position.
Land due diligence checklist
Almost nothing that decides whether a parcel suits you is in the listing. It is in county records, title documents and utility maps. This is the order to work through them, and who to ask.
Land zoning explained
Zoning decides what you are allowed to do with a parcel. It is set locally, it changes, and it is the single most common reason a land purchase does not work out the way the buyer expected.